The present invention relates to a compressor with a transmission.
Japanese Patent Application Publication 2007-107412 discloses a compressor including a housing, a compression mechanism formed in the housing and operable to compress refrigerant, an input shaft extending into the housing from outside and rotatably supported, an output shaft extending in the housing and rotatably supported for driving the compression mechanism, a transmission provided in the housing between the input shaft and the output shaft for transmitting torque from the input shaft to the output shaft and also changing the rotating speed of the output shaft for driving the compression mechanism by increasing or decreasing the rotating speed of the input shaft, and a control device for controlling the operation of the transmission.
The transmission includes a first planetary gear train and a second planetary gear train provided in the front (on the input shaft side) and in the rear (on the output shaft side) in the axial direction thereof, respectively. Each of the first and the second planetary gear trains include a sun gear, a plurality of planetary gears, a carrier retaining respective rotatable planetary gears and a ring gear engaged with respective planetary gears. A thrust bearing and a radial bearing are provided between the respective ring gears and the housing. The ring gear is selectively fixed to or rotatable relative to the housing.
The control device includes a first one-way clutch provided between the ring gear of the first planetary gear train and the housing, a first clutch provided between the ring gear of the first planetary gear train and the carrier, a second one-way clutch provided between the ring gear of the second planetary gear train and the carrier, and a second clutch provided between the ring gear of the second planetary gear train and the housing. The first and the second clutches are operable to engage the respective ring gears selectively with the carrier or with the housing by being displaced in longitudinal direction of the compressor.
The first and the second clutches of the above compressor selectively engage or disengage the respective ring gears independently or simultaneously thereby to allow or prevent the rotation of the respective ring gears relative to the housing or the carrier. Thus, the transmission can change the gear ratio and drive the compression mechanism, accordingly.
However, the structure of the above-described compressor is complicated and, therefore, there has been problems of high manufacturing cost and large noise development due to vibration.
The present invention is directed to providing a compressor with a transmission that can be manufactured at low cost and accomplishes noise reduction.